Steam boiler



'7 Sheets-Sheet 1 Aprilj 30, 1935. E fG. BAILEY Er AL STEAM BOILER' l lFiled Dec. a, 1953 April 30r1935 E. @BAILEY Er AL 1,999,984

STEAM BoILg I Filed Deo. s, `193s 7 sheets-sheet 2 Fig?? 1- f 11 oo oooo o oo o oo oo oo oo oo oo oo oo oo oo oo oo oo po oo oo oo oo oo oo oooo oo oo OO OQ OO 00 00006 OOO 00000 Q00 00000 O00 00000 OOO OOOOINVENTORS Ervzn G. Bazlqy Perry E. Cassm'y BY Pal/gh M Hardgrove Ddl/Id5. Jacobus TToRNEY April 30, 1935.

E. G. BAILEY ET Al.

STEAM BOILER fFiled Dec. a, 1953 '7 Sheets-Sheet 3 INVENTORS VJOS v wruwww@ n mama M @P Ms. m .mUMm A NJW Ewpp l @mi April 30, 1935. E. G.BAILEY Er Al. 1,999,984l STEM BoILER l vFiled Dec. e, 195s 7sheets-sheet 4 asa-1 'g M. Ha y Us ATTORNEY INVENT RS Ervin (oail Perf'E. G. BAILEY ET AL STEAM BOILER- Filed Dec. 8, 1933' Aprl 3o, 1935.-

7 Sheets-Sheet 5 INVENTORS. AErl/111 G. Halley l Perry E. Cassidy BYRalph /1/1. Hardy/'ove Davia' S. Jacabus E. G. BAILEY E-r Al.

STEAM BOILER April 30, 1935. 1,999,984

Filed Dec. s, 19:53 "7 sheets-sheet 6 INYENTORS n Erl/1n G. Baz/ey Perryl?. Cassidy BY Ralph M Hrdgrove ,David S Jacobus Patented Apr, 30, 1935vUNITED sTATEs `PMI-:livr oFFicE 'incassi STEAM riforma pany, Newark, N.J. Jersey a corporation of New Application December s, 193s, sel-iai No.'101,426

v. 29 Claims.

pacity are particularly applicable to industrial vision of a steamboiler of the character de-` plants and marine installations.l

-The general object of our invention is the proscribed which is furthercharacterized by a substantial reduction'in the head-room requirements,a relatively low cost of construction, and a capacity for operation athigh ratings with a low draft loss, good efficiency and high superheattemperatures. A further object is the provision of a furnaceconstruction and arrangement in a steam boiler of thecharacter describedwhich is adapted for the burning of fuel at high efficiencies, andparticularly of a fluid fuel, such as pulverized coal, oil or gas, insuspension. A further object is the provision of a two drum steam boilerof the character described having a highly compact and thermallyeffective arrangement of the fluid heating surface thereof relative tothe boiler furnace and the flow of heating gasesfrom the furnace. Astill further object is the provision of a two drum steam boilerconstruction which is adapted for' standardization in" a series of sizesor classes of different horse power capacities with little or novariation in -the draft loss and exit gas temperature throughout theseries. A .further Object is an improved superheater construction andarrangement in a boiler of the character described in which slagging ofthe superheater tubes is minimized, high steam temperatures obtainedwith a minimum of superheater surface, superheater tube temperaturesmaintained within safe limits, and a relatively 'fiat superheat curveattained. A further specific object is the provision of a low cost uidcooled furnace shaped to provide an effective utilization of its volumefor burning the fuel, and constructed to simplify the boiler supportingstructure,

facilitate the removal of the fuel residue, whether y a part ofI thisspecification. For a better understanding of the invention, itsoperating advantages and specific objects attained by its use,

.have illustrated and described preferred ments of our invention.

Of the drawings:

Fig. 1 is a sectional elevation taken on the line l-I of Fig. 2 andillustrating one embodiment of our invention; Fig. 2 is a plan' sectiontaken on the line 2--2 of Fig. 1; Figs. 3 and 4 are enlarged views ofthe tube bank bailles shown inFig. 2; Fig. 5 is a vertical section takenon the line 5-5 of Fig. 2; Fig. 6 is a vertical sectiontaken on the line6-5 of Fig. 5; Fig. 6A is an enlarged view of a portion of the furnacefloor; Figs. 7 and 8 are elevation and bottom views respectively of theheader connection; Fig. 9 is an enlarged detail of the partition takenon the line 9-9 of Fig. 1; Fig. 10 is a vertical section taken on theline VI (1 -i0 of Fig. 9; Fig. l1 is a vertical section taken on theline lI--II of Fig. 2; Fig. 12 is a vertical section taken on the linel2-I2 of Fig. 2; Fig. 13A is a vertical section taken on the line I3--l3of Fig. 12; Fig. 14 is a sectional elevation of a modified boilerconstruction taken on the line i 1 -ifi of Fig. 16; Fig. 15 is avertical section taken on the line I5-I5 of Fig. 14;r and Fig. 16 is aplan section taken on the line Iii-i6 of Fig. 14.

embodi- In the steam boiler embodying our invention illustrated in Figs.1 to 13 ofthe drawings, 2i! designates an upper horizontally arrangedlongitudinally extending steam and water drum having a submerged feedwater Supply connection and steam outlets 22 adjacent one end. The drum29 is connected to a similarly arranged lower water drum 23 by avertically inclined bank of bent tubes 2t .extending between andconnected to the -drums substantially throughout the length thereof. Thedrum 23 is supported on longitudinally spaced cradles 25 and anchored atits front end for relatively free longitudinal expansion and contractionrearwardly. The drums 29 and 23 and tube bank 2li constitute the mainsteam generating section of the boiler, the weight of these parts beingalmost wholly supported by the cradles 25. The drums 29 and 23 and tubebank 2li are positioned in a housing having vertical refractory frontand rear walls 26 and 2lrespectively, and a side wall 28 at the youterside of the tube bank relative to the furnace. The opposite side wall 29is laterally spaced a substantial distance from the inner side of thetube bank and constructed as hereinafter described. 'Ihe walls 28, 2l,28 and 29 thus form a boiler housing substantiallyrectangular inhorizontal-cross section, as shown in'Fig. 2.'

The space between the inner side of the tube bank 24 and the walls 26,21 and 29 is utilized for the boiler furnace or combustion chamber 30and is arranged to communicate at its rear end with the rear end of thespa/ce 2| occupied by the tube bank 24. The inner side wall 33 of thefurnace chamber terminates short of the rear wall 21, and isadvantageously 'formed by a partition comprising a rowof longitudinallyspaced vertical tubes 24*l having their upper and lower ends connectedto the drums and 23 respectively, and forming the innermost row of thetube bank 24. The tubes 24e are preferably of larger diameter than thetubes 24 in the remaining rows' and spaced from the adjacent row agreater distance transversely of the tube bank than the transversespacing between the remaining rows in the tube bank. The tubes 24, asshown in detail in Figs. 9 and 10, have vertical rows ofstaggered'metallic studs 3| extending along opposite sides thereof andprojecting into the intertube spaces. To prevent spreading of the tubes24a the studs 3| on adjacent tubes are advantageously tied. together atpoints spaced along the tubes. At each of these points the studs on'adjacent tubes are welded by jump welds to a vertical plate 3 2positioned between the stud rows. The use of the plates 32 facilitatesthe manufacture 'and` assembly of the stud tubes. The intertube spacescontaining the studs 3| are closed by suitable refractory material 33aapplied in an initially plastic state and allowed to,set. The partitionor wall 33 so formed extends only a portion of the length of the tubebank, leaving a space between its rear end and the rear wall 21 throughwhich the furnace chamber and the tube space communicate. The tubes 24ereceive heat on one side by radiation from the furnace chamber and onthe opposite side by convection from the tube space.

The outer side wall 23 of the furnace chamber has its inner portionformed in substantially the same manner as lthe inner wall 33 `by a rowof vertically arranged radiantly heated stud tubes 3.4 uniformly spacedthroughoutthe length of the furnace chamber and refractory material 35closing the intertube spaces and supported by the tube studs, as inFigs. 9 and 10. The tubes 34 have their lower ends connected to asubstantially horizontal header 36 extending longitudinally of thefurnace chamber slightly above the level of the axis of the mud drum 23and supported on longitudinally spaced piers 33. The upper portions ofthe tubes 34 are similarly ,curved and inclined toward the tube bank 24and connected into the drum 20 above the level of the tubes 24e and ator below the normalwater Y closed by heat resistant. blocks 4|, the atupper 10- level in the drum. 'I'he tubes 34 thus define the outer sidewall and roof of the furnace chamber 30. One or more layers 31 ofinsulating material are arranged between the outer side of the tubes 34and an outer metallic casing 38.

The floor of the furnace chamber is defined by a row of horizontallyinclined radiantly heated water tubes 40 connecting the drum 23 to theheader 36. The tubes 40, 24e and 34 are substantially similarly spacedthroughout most'of the length of the furnace chamber and the tubes 40are covered and the spaces therebetween surfaces of which constitute asmooth :door extending from the front wall 2 6 to an ash pit 42 at therear end of the furnace chamber. The blocks 4| are preferably secured tothe tubes 46 by clamps 4| bridging adjacent tubes and c911- -nected tothe blocks 4I, as shown in 6a. The

one or more fluid fuels, such as pulverized coal,

oil or gas, simultaneously or independently. The fuel burner issymmetrically arranged in the front wall 26 to discharge a stream offuel horizontally through the furnace chamber toward its rear wall 21.

The stream of fuel directed. toward the rear 'wall of the furnacechamber might cause that wall to rapidly erode at high rates ofoperation or when a fuel having a low fusion ash is burned, and in thepresent construction the inner face of the rear wall is advantageouslyprotected by a row-of transversely spaced vertical cooling tubes 50,arranged as shown in Figs. 1, 2 and 5. The tubes 50 have their lowerends connected to a horizontally inclined header 5| having its axis inhorizontal alignment. with the axes of the floor tubes 40 and with theheader end adjacent the drum 23 connected thereto` by a nipple 52. Theupper portions of the tubes 56 are bent substantially parallel to thetubes 34 and connected in a circumferential row to the steam and waterdrum 20. The lower ends of certain rear wall tubes 50 are bentoppositely at opposite sides of clean-out openings 53 and inspection orlance openings 54. Similar openings are also made in the refractoryfront wall 26. 'The tubes 50and header 5I are slightly spaced from therear wall to permit rearward movement thereof on expansion of the boilerdrums and/or header 36.

In order to facilitate closing the corner of the furnace between thewalls 21 and 29, an additional oor tube 40 is provided alongside theheader 5|. The upper lsurfaces of the header 5| and tube 40a areprotected by a layer of refractory 55. In operation, the floor tubestend to expand axially and move the header 36 laterally. The tube 40being widely spaced from the adjacent tube 40 would have little effecton the corresponding portion of the header 36. To prevent deformation ofthe tube 40"L on expansion thereof and to provide simultaneouslymovement of the headers 5| and 36 on elongation of the latter, a plate56 is welded to the underside of the header 36 andprovided with anopening 51 in a portion thereof below the header 5| into which a lug 58on the underside of the header 5| fits.

' The ash pit 42 in the furnace illustrated extends across the rear endof the furnace chamber in front of the rear wall 21, in which is formeda series of spaced clean-out openings 59`closed by doors 60. The ash pithas a refractoryiioor 6|, si'de walls 62, and a vertical front wall 63,which has a seal joint permitting relative longitudinal expansion of thefurnace floor. The last pair of floor tubes 40 are connected by a spacerbar 4||b welded thereto, as shown in Fig. 6A. A

seal plate 4|| extends downwardly from the lower side of the last tube40. The joints between the ash pit walls`62 and the header 36 and drum23 are protected by a refractory layer, the rear portion of the header36 being studdedas shown in Fig. 5, to hold the refractory inposition.The furnace floor may be cleaned by'tools inserted through the openings58 and the fuel residue collected removed from the ash pit through theopenings 58 at the boiler room floor level. The oor and ash pitconstruction may be changed or the ash pit omitted depending upon .thecharacter of the fuel burned and the condition of the fuel residuedeposited on the furnace oor. Where, for example, the fuel burningprovisions are not intended for burning an ash-forming fuel, the ash pitmay be omitted and the furnace fioor continued to the rear wail'21.

In prior two-drum boiler constructions of the general characterdescribed, it has been customary to cause the heating gases to flowhorizontally through a single pass longitudinally of the convectionheated tube bank. Such a construction is not practical for. the basis ofa commercial line of boilers having different maximum steam generatingcapacities while maintaining substantially the same draft loss and exitgas temperature. The addition of steam) generating surface in suchboilers results either in an undesirable change in the furnace shape, anundesirable decrease in the-drum ligament strength, or an in: crease inthe draft loss. The single pass arrangement is further disadvantageousas it offers substantially no flexibility of control of the mass flow ofheating gases over the tube bank. With the present construction, aseries of boiler sizes with similar tube spacings may be obtained whilemaintaining substantially the same draft loss and without changing thefurnace transverse cross-sectional area and shape, by merely changingthe total number of transverse rows of tubes Iand correspondingly:changing the number of y 2, the tube bank space 2| is advantageouslydivided into a plurality ofv serially connected gas passes 18, 1I and12, extending transversely of the tube bank and through which asubstantially horizontal iow of heating gases is maintained from thefurnace chamber to a gas outlet 13 in the front end of a at arch 14extending between the drum 2@ and housing wall 28. Sloping baffles 15and 16 separate the. gas passes 18, 1| and 12. As shown in Figs. 2, 3,12 and 13, the baille 15 extends between the drums from the innerfurnace chamber wall 33 toward the housing wall 28 terminating short ofthe latter to permit communication between the gas passes 1li and 1l. Apair of tubes 24b at the rear end of the chamber wall have studs 3 i ontheir outer sides which support a layer of refractory material 33h inwhich a notch 11 is formed to receive the inner end of the baffle 15.The baffle 15 is formed by superposed rows of tile, as shown in Fig. 12,which are held between thelast transverse row of tubes 24 and atransverse row of large diameter tubes 28C hereinafter described. Thesuperposed tile 'iiia adjacent the furnace chamber wall 33 are providedwith tongue and groove joints, as shown gaspass 1,0 are fewer in numberbut of' greater diameter than the tubes in the second and third passes'H and 12. The tubes of the innermost rows in the nrst pass are bent andstaggered, as shown in Figs. 2 and 11, to form a slag screen across theentrance end of the first pass. The remaining steam generating tubes 24are arranged in longitudinal rows occupying only about one-half of theavailable space in the first pass. The tubes 24u serve as a water screenfor a steam superheater positioned'in the first pass between the tubes24c and the wall 28.

The steam superheater is formed by a series of nested single loopedtubes 88 arranged substantially parallel to'the tubes 24 with theirlooped portions adjacent the drum 20 and their lower ends connected to apair of longitudinally extending horizontal headers'ii I and 82 betweenthe drum 23"and wall 28. The headers 8| and 82 are partitioned, asindicated in Fig. 2, to divide the superheater into passes for theserial flow of the steam therethrough. The header 82 receives the steamto be superheated at its forward end through the tubes 22 and has anoutlet 82n formed on its rear endfor the discharge of the superheatedsteam. The superheater is supported entirely by the drum 23 throughlongitudinally,

spaced cantilever beams 83 in which the super- Aheater headers are.cradled. The superheater tube connections' and lower supports are pro-The horizontal load of the upper end of 24 through lugs 85 welded to theboiler tubes and opposite the superheater tubes, and transverse spacers86a and longitudinal spacers 86 for holding the superheater tubes inspaced relation.

The amount of steam generating surface in the first pass is limited tothat required to remove the slag from the furnace gases and to reducethe gas temperature to a value at which safe superheater tubetemperatures result. With only this amount of steam generating surfacecontacting with the furnace gasesprior to their reaching thesuperheater, only a relatively small amount of superheater surface willbe required to obtain a given steam superheat temperature and a lessvarying superheat curve will result. The use of large diameter tubes inthe first pass is desirable with the high gas temperatures present. Theuse of small diameter superheater tubes in the rst pass and 'steamrgenerating tubes in the lsecond and third passes reduces the cost andspace requirements and increases the boiler efficiency for a givenamount of heating surface. The boiler and superheater tubes in the firstpass can be easily'removed and replacedfrom the furnace chamber.

With the boiler construction described, feed water enters the drum 28and flows downwardly throughsubstantially all of the tubes 24 in the gaspasses 1I and 12. A considerable portion of the steam is generated inthe furnace tubes 2li, 40 and 34 and the tubes 2lic in the first'pass.Fuel is preferably introduced through the front wall into the furnacechamber in a horizontal stream andis rapidly ignited `and burned'insuspension. The heating gases pass rearwardly through the furnacechamber and then transversely across the slag and water screen tubes2lic Y in the gas pass 1l). The gases then contact with the superheatertubes 80 and turn around the baiie 15 into thegas pass 1 i After passingacross the tubes 24 in the gas pass 1i, the gases turn through the space81 between the innermost row of small diameter tubes 24 andthe innerfurnace wall 33, the space 81 insuring proper distribution of theheating gases in the passes 1| and 12 and minimizing the amount of tubesurface therein short-circuited. The heating gases tend to rise duringtheir passage through the gas passes'and to prevent by-passing of thelower portions of the tubes in the third pass 12, spaced metal stripbaffles 88 are mounted on the outermost tubes 24 in that pass, as shownin Fig. 1,' to cause most of the gases to turn downwardly below thebailied section before reaching the boiler gas outlet 13. Dampers 89control the gas outlets 13. A brick wall 90 i's constructed at the frontend of the refractory layer 84 to prevent the heating gases entering thespace containing the superheater supports. The' uid heating surface inthe furnace shown is preferably proportioned in amount and exposure tomaintain a furnace temperature such that when a slag-,forming fuel isburned in suspension, a substantial portion of the particles of fuelresidue deposited on the furnace floor will be cooled sumciently topermit their removal in a dry form.

The steam and water drum 20 contains suitable steam and water separatingprovisons for insuring the delivery of substantially dry steam to thesuperheater. The separator is preferably of the type disclosed andclaimed in a pending application of James Fletcher, Serial No. 678,374,filed June 30, 1933. l

While the Whole vertical load of the drums and tube bank is carried bythe supports for the mud drum, the vertically inclined arrangement ofthe tube bank and offsetting of the drums causes a horizontal load whichis partly supported by the tubes 34 and the floor supports and partly byend horizontal beams 92 each having an inclined bracket 93 in contactwith a similar bracket 84 on the drum, as shown in Fig. 1l.

In the modification illustrated in Figs.. 14 to 16 the upper and` lowerdrums |20 and |23 have their axes substantially in vertical alignmentand the connecting tubes |24 upright. 'I'he inner wall of the `furnace|30 is formed by a refractory baille |33 supported between the innermostrow of smallv diameter tubes |24 and a row of large diameter tubes |24".The innermost row of tubes |24 is laterally spaced from the remainingtube rows a substantial distance to provide a gas turning space |81therebetween. The oor, outer side wall I 29, and roof of the furnace aredefined by a row ci! longitudinally spaced continuous U-shaped tubes |34having their oppositeends connectedto drums |20 and |23 respectively.'I'he tubes |34 line the 'inner surfaces of the refractory forming thefloor, outer side wall, and roof. The rear walldivided into seriallyconnected transverse gas` passes |60, |6|, and |62 byrefractory baflles|64 and |65. 'I'he baille |64 forms a perpendicular extension of therear end of the baille |33, while the baille |65 extends from thehousing wall |28 towards, but terminating short of, the baille wall |33.The tubes |24a at the outer side of the baille |33 are uniformlyl spacedthroughout the length of the furnace, extending across the entrance tothe gas pass |60. The tubes |24 are similarly dis tributed and arrangedin all of the gas passes, and those in the gas pass |60 provide a waterscreen for the superheater |80.- The superheater is formed by one ormore large diameter looped tubes extending horizontally along the outerside of |22 of the drum |20, and provided with a drain connection |82 atits lowermost point to make the superheater self-draining.

With the above construction a stream of fluid fuel is projectedhorizontally toward the rear wall of the furnace, and the products ofcombustion pass rearwardly around the rear end of the baille wall |33and successively through the heating gas passes |60, |6| and |62 to theheating gas outlet |63. The fluid ow in the boiler circulation systemwill be substantially the same as that described in the embodimentillustrated in Figs. l to 13, the ilow through the radiant heatabsorbing furnace tubes and the steam generating tubes in the gas pass|60 being upward, while the flow through the tubes located in the passes|6| and |62 is generally downward. A considerable portion of the steamgenerated in the tube bank will be in the tubes located in the gas pass|60, and thesteam'outlet |22 from the drum |20 is located at the frontend of the drum.

While in accordance with the provisions of the statutes we haveillustrated and described herein the best forms of our invention nowknown to us, those skilled in the art will understand that changes maybe made in the form of the boiler, furnace and fuel burning provisionsdisclosed without departing from the spirit of the invention covered byour claims, and that certain features of our invention may sometimes beused to advantage without a corresponding use of other features. s

We claim:

1. A steam boiler having an upper steam and water drum, a lower waterdrum, a vertically disposed convection heated bank of steam generatingtubes extending between and connected to said drums along the lengththereof, means forming a furnace chamber laterally adjoining the spacecontaining said tube bank and communicating therewith at only one end,baille means extending transversely of said tube space and arranged todivide said tube space into a plurality of serially connected gas passesextending transversely 4of said tube bank, and means at the opposite endof said furnace chamber for burning fuel in said furnace chamber andeffecting a substantially horizontal flow of heating gaseslongitudinally through said furnace chamber and reversely through saidserially connected gas passes.

2. A steam boiler having van upper steam and water drum, a lower waterdrum, a vertically disposed convection heated bank of steam generatingtubes extending between and connected to said drums along the lengththereof, means forming a fluid cooled furnace chamber laterallyadjoining lthe space containing said tube bank and communicatingtherewith only at one end, means at the opposite end of said furnacechamber for burning fuel in suspension iny said furnace chamber andeffecting a substantially horizontal flow of heating gaseslongitudinally through said furnace chamber and reversely through saidtube space, and transversely extending baille means arranged to dividesaid tube space .into a plurality of serially connected gas passesextending transversely of said tube bank.

3. A steam boiler having a substantially rectangular housing, en uppersteam and water drum, an offset lower water drum, avvertically inclinedconvection heated bank of closely spaced steam generating tubesextending between andl connected to said drumssubstantially throughoutthe length thereof, a baille wall separating a laterally adjoiningfurnace chamber from the space containing said tube bank and terminatingat its rear end short of the rear wall of said housing to providecommunication therebetween at their rear ends only. a row of water tubesconnected to said drums and in thermal contact with said partition,lanother row of water tubes connected to said drums-and laterally spacedfrom said tube bank and extending along the outer side wall of saidfurnace chamber, meansiat the front end of said furnace chamber forburning fuel in suspension in said furnace chamber and effecting asubstantially horizontal flow of heatying gases longitudinally throughsaid furnace chamber and reversely through said tube space, transverselyextending baffle means arranged to divide said tube space into aplurality of serially connected gas passes extending transversely ofsaid tube bank, and'said partition and partition cooling tubes beingspaced from the adjacent tube bank row of tubes a transverse distancegreater than the transverse distance between the longitudinal tube rowsin the gas passes laterally adjoining said partition.

4. A steam boiler having an upper steam and water drum, a lower waterdrum, a vertically disposed convection heated bank of steam generatingtubes extending between and'connected to said drums along the lengththereof, a partition defining the inner side wall of a furnace chamberlaterally adjoining the space containing said tube bank andcommunicating therewith at one end..

fuel burning means at the opposite end of said furnace chamber, meanseffecting a substantially horizontal flow of heating gaseslongitudinally through said furnace chamber and reversely through saidtube space, transversely extending baffle means arranged to divide saidtube space into a plurality of serially connected gas passesextendingjransversely of said tube bank, and

' the tubes of said tube bank in the gas pass opening to saidfurnacechamber being of larger diameter than the tubes in the subsequent gaspasses.

5. A steam boiler having an upper steam and water drum, a lower waterdrum, a vertically disposed convection heated bank of steam generatingtubes extending between and connected to said drums alongthe lengththereof, means forming a fluid cooled furnace Achamber laterally ad-.joining the space containing said tube bank and communicating therewithat one end, said means including a row of vertically disposed watertubes laterally spaced from said tube bank and having ,their upper endsconnected to said steam and water drum, integral projections on saidwater tubes, refractory. material carried yby said tube projections anddefining the outer sidewall of said furnace chamber, tubes connectingthe lower ends of said side wall tubes to said lower drum,

, and means at the opposite end of said furnace chamber for burning fuelin suspension in said furnace chamber and effecting a substantiallyhorizon-tal flow of heating-gases longitudinally through said kfurnacechamber and reversely through said tube space and in thermal contactwith'the tubes therein.

6. A steam boiler having an upper steam and water drum, a lower waterdrum, a vertically disposed convection heatedbank of steam generatingtubes extending between and connected to said drums along the lengththereof, means formv ing a fluid cooled furnace chamber lateralllradjoining the space containing said tube bank and communicatingtherewith at one end, said means including a row of vertically disposedwater tubes l laterally spaced from said tube bank and-having theirupper ends connected to'said steam and water drum, refractory materialvclosing the spacesl of heating gases longitudinally through said furnacechamber and thence through said tube space and in thermal contact withthe tubes therein.

7. A steam boiler-having an upper steam and water drum, a lower waterdrum, a vertically disposed convection heated bank of steam generatingtubes extending between and connected to said drums along the lengththereof, means forming av fluid cooled furnace chamber laterallyadjoining the space containing said tube bank and communicatingtherewith at one end, said means including a row of vertically disposedwater tubes laterally'spaced from said tube bank andhaving their upperends directly connected to said steam and water drum, refractorymaterial closing the spaces between said water tubes and deflning theouter side wall and roof of said furnace chamber, a header connectedtothe lower ends of said water tubes, a row of tubes connecting saidheader to said lower drum, refractory means closing the spaces betweenand covering said last named' tubes to define the iioor of said furnacechamber, a fluid cooled partition extending between said drums adjacentthe`forward portion of said tube bank and defining the inner side wallof said furnace chamber,and means at the opposite end of said .furnacechamber for burning fuel in suspension in said combustion chamber andeffecting a substantially horizontal flow of heating gaseslongitudinally through said furnace chamber and reversely through saidtube space and in thermal contact with the tubes therein.

8. A steam boiler having an upper steam and water drum, a lower waterdrum, a vertically disposed convection heated bank of steam generatingtubes lextending between and connected to said drums along the lengththereof, a partition deflning the inner side wall of a furnace chamberlaterally adjoining the space containing said tube bank andcommunicating therewith at its rear end, means at the front end of saidboiler for burning a slag-forming fuel in said furnace chamber andeffecting a substantially horizontal flow of heating gases rearwardlythrough said furnace chamber and thence through said tube space and inthermal contact with the tubes therein, and means adjacent the rear endof said waterdrum, a lower water drum, a vertically disposed convectionheated bank of steam generating tubes extending between and connected tosaid drums along the defining the inner side wall of a furnace chamberlaterally adjoining the space containing said tube bank andcommunicating therewith at one end, a row of water tubes connected tosaid drums and laterally spaced from said tube bank and extending alongthe outer side wall of said furnace chamber, a horizontal headerconnected to the lower ends of said side wall tubes, means at theopposite end of said furnace chamber for burning fuel in suspension insaid furnace chamber and effecting a substantially horizontal ow ofheating gases longitudinally through said furnace chamber' and reverselythrough said tube space, a horizontally extending header along the rearwall of said furnace chamber and connected to said lower water drum, arow of tubes connecting said rear wall'header and steam and water drum'and cooling the rear wall of said furnace chamber, and means forming adirect structural connection between said side and rear wall headers.

10, In 1a furnace, a wall comprising a row of spaced tubes, amultiplicity of metallic studs mounted on opposite sides of said tubesand projecting into the inter-tube spaces, refractory material carriedby said studs and closing the inter-tube spaces, and means for tyingadjacent tubes together at a point intermediate their length comprisingmeans forming a welded con-- nection between studs on adjacent tubes.

.11. In a furnace, a wall comprising a row of spaced tubes, amultiplicity of metallic studs mounted on opposite sides of said tubesand projecting into the inter-tube spaces, refractory ma terial carriedby said studs and closing the intertube spaces, and means for tyingadjacent tubes together intermediate their length comprising a plateextending vertically between the studs on adjacent tubes and weldsintegrally connecting 4 said plate to studs on adjacent tubes.

12. In a tubular heat exchanger adapted as a part of a furnace wall totransmit to a contained fluid the heat received radiantly from fuelburni ing in the furnace; said tubular heat exchanger having a metallicinner part in contact with the contained uid; and a composite buterstructure exposed to radiant heat from the burning fuel; said outerstructure comprising metallic projections extending outwardly from theinner part, and refractory material contacting with the inner part Iandlocated between the projections, said refractory material being ofgreater,therma1 resistanc than themmaterial of the remaining structure,thereby preventing overheating of the exchanger metal and contributingto higher furnace temperatures, and means for integrally connecting themetallic projections on adjacent tubes.

13. A steam boiler having an upper steam and water drum; a lower waterdrum, a vertically disposed convection heated bank of steam generatingtubes extending between and connected to said drums along the lengththereof, a partition defining the inner side wall of a furnace chamberlaterally adjoining the space containing said tube bank andcommunicatingA therewith at one end, means defining the remaining wallsof said furnace 'chamber and tubeV space, means at the opposite end ofsaid furnace chamber for burning fuel in said furnace chamber andeffecting a substantially horizontal ow of heating gases longitudinallythrough said furnace chamber and reversely through said tube space andin thermal length thereof, a partition contact with the tubes ranged todivide said tube space into a plurality of serially connected gas passesextending transversely of said tube bank, and a .stear superheaterpositioned in the gas pass opening to' said furnace chamber.'

14. -A steam boiler having an upper steam and water drum. a lower waterdrum, a vertically disposed convection heated bank of steam generatingtubes extending between and connected to said drums along the lengththereof, a partition defining th'e inner side wall of a furnace chamberlaterallyadjoining the space containing said tube bank and communicatingtherewith only at one end, means dening the remaining walls of saidfurnace chamber and tube space, means at the opposite end of saidfurnace 'chamber for burning fuel in said furnace chamber and effectinga substantially horizontal iiowbf heating gases longitudinally throughsaid furnace chamber and reversely through said tube space and inthermal contact with' the tubes therein. baille means arranged to dividesaid tube space into a plurality of serially 'connected gas passesextending transversely of said tube bank, a steam superheater positionedin the gas pass opening to said furnace chamber, and water tubes in saidlast mentioned gas pass arranged to-form a screen between saidsuperheater and ysaid furnace chamber.

l5. A steam boiler having an upper steam and water drum, a lower waterdrum, a vertically disposed convection heated bank of steam generatingtubes extending between and. connected to said drums along the lengththereof, a partition taining said tube bank and communicating therewithonly at one end, a row of spaced verticallydisposed water tubesllaterally spaced fromsaid tube bank and connected to said steam andwater drum, refractory material closing the spaces between said watertubes and defining the outer side wall of said furnace chamber, a headerconnected to the lower end of said water tubes, a row of tubesconnecting said header to said lower drum, means closing the spacesbetween said last named vtubes and defining the floor of said furnacechamber. means at the opposite end of said furnace chamber for burningfuel in suspension in said furnace chamber and effecting avsubstantially horizontal flow of heating gases longitudinally throughsaid furnace chamber and thence through said tube space and in thermalcontact with the tubes therein, and an ash receiving opening extendingtransversely of said furnace chamber atthe rear of said floor tubes.

16; A steam boiler having an upper steam and water drum, a lower waterldrum, a vertically disposed convection heated bank o'f steam generatingtubes extending between and connected to said drums alonglthe lengththereof, va bottom support for said drums and tube bank, means forming afurnace chamber laterally adjoining the space containing said tube bankand communicating therewith at its rear end, means at the front end ofsaid furnace chamber. for-buming fuel in said furnace chamber andeffecting a substantially horizontal ow of heating gases rearwardlythrough' said furnace chamber and forwardly through said tube space, asuperheater at the outer side of said tube bank having a pair of headersarranged parallel to said lower water drum 'and looped tubes connectingsaid headers arranged adjacent said tube bank, means for supporting saidheaders from said lower water therein, baille means'ardrum, and meansforv laterally supporting said iboped tubes imm said tube bank.

17. Asteam boiler having an upper steam and water drum, a lower waterdrum, a vertically disposed convection heated bank of steam generatingtubes extending between and connected to said drums along the lengththereof, means defining a furnace chamber laterally adjoining the spacecontaining said tube bank and including a row of tubes having one endconnected to said lower drum and extending laterally from said tubebank, a horizontal side -wall header connected to the other end of saidlaterally extending tubes, means for burning fuel in said furnacechamber, a header extending along an end wall of said furnace chambersubstantially parallel to said laterally extending tubes and connectedto said lower drum, a row of tubes connecting said end wall header tosaid upper drum, and means forming a direct structural connectionbetween said side and end wall headers.

18. A steam boiler having an upper steam and lwater drum, a lower waterdrum, a vertically disposed convection heated bank of steam generatingtubes extending between and connected to said drums along the lengththereof, a partition defining the inner side wall of a furnace chamberlaterally adjoining the space containing said tube bank andcommunicating therewith at its rear end only, means defining theremaining walls of said furnace chamber and tube space, a row of tubesconnected to said upper drum and laterally spaced from said tube bankand extending along the outer side wall of said furnace chamber, ahorizontal header connected to the lower ends of said side wall tubes, arow of tubes extending laterally'from said lower drum and connectingsaid lower drum to said side wall header, means at lthe front end ofsaid furnace chamber for burning fuel in suspension therein andeffecting a substantially horizontal ilow of heating gases rearwardlythrough said furnace chamber and thence through said tube space, ahorizontally extending header along the rear wall of said furnacechamber and connected to said lower water drum, and a row of spacedtubes connecting said rear wall header to said upper drum and arrangedto cool the rear wall of said furnace chamber.

19. A steam boiler having an upper steam and water drum, a lower waterdrum, a vertically disposed convection heated bank of steam generatingtubes extending between and connected to said drums along the lengththereof, means defining a furnace chamber laterally adjoining the spacecontaining said tube bank and including a row of spaced tubes extendinglaterally from and connected to said lower drum, means closing thespaces between said laterally extending tubes and dening the floor ofsaid furnace chamber, means at the front end of said furnace chamber forburning fuel in suspension therein, and an ash receiving openingextending transversely of said furnace chamber at the rear end thereof.

20. A steam boiler having an upper steam and water drum, a lower waterdrum, a bank of steam generating tubes extending between and connectedto said drums along the length thereof,

'means forming a furnace chamber laterally adjoining the spacecontaining said tube bank 4and communicating therewith at its rear end,means at the front end of said furnace chamber for burning fuel in saidfurnace chamber and eifecting a substantially horizontal iiow of heatinggases rearwardly through said furnace chamber and thence through saidtube space, baille means extending transversely of said tube space andarranged to divide said tube space into a plurality of seriallyconnected gas passes extending transversely of said tube bank, steamsuperheating tubes positioned in the gas pass opening to said furnacechamber and at the outer side of said tube bank, and means forsupporting,s'aid superheating tubes from said tube bank.

21. A steam boiler comprising an upper steam and water drum, a lowerwater drum, a vertically disposed convection heated bank of steamgenerating tubes extending between and connected to said drums along thelength thereof, a partition forming the inner side of a furnace chamberand separating the same from a laterally adjoining space containing saidtube bank, means dening the remaining sides of said furnace chamber andtube space, said furnace chamber and tube space communicating at theirrear ends only, means at the front end of said furnace chamber forburning fuel and effecting a substantially horizontalilow of heatinggases rearwardly through said furnace chamber and thence through saidtube space, and the tubes in the tube rows at the rear end of said banknearest said furnace chamber being spaced apart a greater distance thanthe tubes in the remaining rows of said bank to form a slag screenbetween the tubes in the remaining rows and said furnace chamber.

22. A steam boiler comprising an upper steam and water drum, a lowerwater drum, a vertically disposed convection heated bank of steamgenerating tubes extending between and connected to said drums along thelength thereof, a partition forming the inner side of a furnace chamberand separating the same from a laterally adjoining space containing saidtube bank, means defining the remaining sides of said furnace chamberand tube space, said furnace chamber and tube space communicating attheir rear ends only, means at the front end of said furnace chamber forburning fuel and eifecting a substantially horizontal iiow of heatinggases rearwardly through said furnace chamber and thence through saidtube space, the tubes in the tube rows at the rear end of said banknearest said furnace chamber being spaced apart a greater distance thanthe tubes in theremaining rows of said bank' to form a slag screenbetween the tubes in the remaining rows and said furnace chamber, and asteam superheater positioned in. said tube space at the opposite side ofsaid tube bank from said furnace chamber.

23. A steam boiler having an upper steam and water drum, a lower waterdrum, a vertically disposed convection heated bank of steam generatingtubes extending between and connected to said drums along the lengththereof and disposed at both sides of the plane including thelongitudinal l for burning fuel and effecting a substantially horizontalflow of heating gases longitudinally through said furnace chamber and"thence,

through said tube space, and a steam superheater positioned in said tubespace on the side of said axial plane opposite said furnace chamber.

24. A steam boiler comprising an upper steam and water drum. a lowerwater drum, a vertically disposed convection heated bank of steamgenerating tubes extending between and connected to said drums along thelength thereof, a partition forming the inner side of a furnace chamberand separating the same froma laterally adjoining space containing saidtube bank, means defining the remaining sides of' said furnace chamberand tube space, said furnace chamber and tube space communicating attheir rear ends only, a row of tubes connected to said drums andlaterally spaced from said partition and extending along the outer sideof said furnace chamber, means at the front end of said furnace chamberfor burning fuel and effecting a substantially horizontal flow ,-ofheating gases rearwardly through said 4furnace chamber and thencethrough said tube space, and vertical baille means extending from saidupper drum to said lower drum and arranged transversely of said tubebank to divide said tube space,into a plurality of serially connectedgas passes having a substantially horizontal flow of heating gasestherein in thermal contact with said tube bank.

25. In a uid heater, a furnace boundary structure adapted to be exposedin operation to high temperatures and comprising a row of spaced fiuidheating tubes, a series of metallic projections mounted on said tubesand arranged to project into the intertube spaces, refractory materialbetween said projections in contact with said tubes and arranged toclose the intertubespaces, and means for connecting projectionson'adjacent tubes.

26. In a fluid heater,l a separating `wall4having opposite sides adaptedto be exposed in operation to high temperatures and comprising a row ofvertically disposed spaced fluid heating tubes, a series of metallicprojections mounted on said tubes and arranged to project into theintertube spaces, refractory material between said projections incontact with said tubes and arranged to close the intertube spaces, andmeans for 1ntegrally connecting projections on adjacent tubes.

27. In a uid heater, a row of spaced fluid heating tubes having a seriesof metallic projections mounted on and spaced along opposite sides ofsaid tubes, and arranged to project into the inter-tube spaces,andconnecting means between projections on adjacent tubes to tie saidtubes together along their length.

28. A steam boiler having a pair of'horizontally disposed upper andlower drums, a bank of vertically disposed water tubes 'extendingbetween and connected to saiddrums along the length thereof, meansforming a longitudinally extending combustion lane and a heating lanelaterally adjoining said combustion lane and containing said tube bankand communicating with said combustion lane at one end thereof, saidmeans including a vertically disposed partition extending along one sideof said heating lan'e and having tubes' provided withrefractory-supporting'- metallic projections at the heating lane sidethereof arranged to form a vertically extending recess, a verticallydisposed baille extending.'

transversely of said heating lane and fitting into the recess in 'saidpartition, and means for burning fuel in said combustion lane andarranged to permit a serial fiow of heating gases through saidcombustion and heating lanes.

29. A steam boiler having a pair of horizontally disposed upper andlower drums, a bank of ver- 1 tically disposed water tubes extendingbetween and connected to said drums along the length thereof, meansforming a longitudinally extend` y ing combustion lane and a heatinglane laterally adjoining said combustion lane and containing saidtubebank and communicating with said combustion lane at one end thereof,said means including a row of tubes with refractory materialtherebetween and forming a vertically disposed longitudinally vextendingpartition separating and forming one side of said combustion and heatinglanes, means for burning fuel in said combustion lane and arranged topermit a serial flow of heating gases through said combustion andheating lanes, and said partition and partition-forming tubes beingspaced a substantial distance from the laterally adjacent tubes of saidtube bank to provide a heating gas distribution space between saidpartition and tube bank.

ERVIN G. BAILEY. PERRY R. CASSIDY. RALPH M. HARDGROVE. DAVID S. JACOBUS.

CERTIFICATE or CORRECTION.

mem No. 1,999, 984. Ami 3o. |935.

ERVIN G. BAILEY, ET AL.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 2,second column,

' line 52,- for "simultaneously" read simultaneous; pageS. first column,line l0, claim 3, for "baffle wall" reud'parttion; and that the saidLetters Patent should be read with these corrections therein that thesame. may conform to vthe record of the case in the Patent Office.

* Signed and sealed this 16th day of July, A. D. 1935.

Leslie Frazer (Seal) Q Acting Commissioner of Patents. i

